This invention relates to deep water mooring terminals and more particularly to improvements therein.
Because of the draft required for oil tankers nowadays, these tankers are moored with deep water mooring facility at some distance off-shore. These mooring facilities can comprise mooring buoys as well as mooring towers which are attached to the bottom of the ocean by means of a swivel joint. Provision is also made for pipes extending along the bottom of the ocean from stations on land, or from supply vessels, up to the mooring buoy or through the mooring tower from whence hoses extend to the tanker.
Heretofore a tanker would be moored to a buoy or a column by hawsers. However, one type of mooring which is presently coming into favor, is to use a V-shaped structure with a buoy which has the apex of the V attached to the buoy and a ship can then sail into the opening of the V, the arms of which have suitable arrangements thereon for coupling to the ship. Hoses normally used for carrying liquid cargo to or from the ship are replaced by pipes which are supported by the V arms and therefore can be readily coupled to the pipelines on the ship. This avoids the necessity for having a tug pickup the hoses and mooring lines from the ocean surface from which they otherwise are floated and carry them to the tanker. Another use for this type of mooring is to have a vessel permanently moored to the buoy. It supplies other ships with liquid cargo which it receives from the buoy.
The V-shaped mooring arrangement can swivel around the vertical axis of a buoy, but all other motions of the ship are communicated through the V-shaped mooring mechanism and are absorbed by moving the buoy.
In the case of the mooring columns, no V-shaped mooring mechanism has been provided. Mooring thereto is achieved by mooring hawsers. The reason apparently is that in view of the fact that the mooring column is a rigid structure, it would not be able to absorb the forces transmitted through a rigid mooring mechanism by the moored ship. A V-shaped mooring arrangement which can be used with a mooring column would provide advantages, such as ease of mooring, and would eliminate the need for hoses and hawsers which deteriorate and require replacement.